fileutil.c

NUcleus plus 支持的文件系统。 是学习文件系统的很好参考资料。

*       Returns NULL on a bad drive number otherwise a pointer to the   
*       first character in the rest of the path specifier.              
*                                                                       
*************************************************************************/
UINT8 *pc_parsedrive(INT16 *driveno, UINT8  *path)
{
UINT8       *p = path;
INT16       dno = -1;


    /* get drive no */
    if ( p && *p && (*(p+1) == ':') )
    {
        if ( ((*p) >= 'A') && ((*p) <= 'Z') )
            dno = (INT16) (*p - 'A');
        if ( ((*p) >= 'a') && ((*p) <= 'z') )
            dno = (INT16) (*p - 'a');
        p += 2;
    }
    else
        dno = NU_Get_Default_Drive();

    if ( (dno < 0) || (dno >= NDRIVES) )
        return(NULL);
    else
    {
        *driveno = dno;
        return(p);
    }
}


/************************************************************************
* FUNCTION                                                              
*                                                                       
*       pc_parsenewname                                                 
*                                                                       
* DESCRIPTION                                                           
*                                                                       
*       If use wild card, setup the new file name.                      
*                                                                       
* AUTHOR                                                                
*                                                                       
*       Kyoichiro Toda
*                                                                       
* INPUTS                                                                
*                                                                       
*       *pfi                                File directory entry        
*       **newname                           File name(wild card)        
*       **newext                            File extension(wild card)   
*       *fname                              File name buffer            
*                                                                       
* OUTPUTS                                                               
*                                                                       
*       Always YES                          Success compleate.          
*                                                                       
*************************************************************************/
INT pc_parsenewname(DROBJ *pobj, UINT8 *name, UINT8 *ext, 
                    VOID **new_name, VOID **new_ext, UINT8 *fname)
{
LNAMINFO    *linfo;
DOSINODE    pi;
UINT8       *p;
UINT8       *old;
UINT8       *op_nmend;
UINT8       *op_exend;
UINT8       old_name[EMAXPATH+1];
FINODE      *pfi;


    *new_name = *new_ext = '\0';

    /* get long file name info */
    linfo = &pobj->linfo;

    /* Setup the old file name */
    if (linfo->lnament)             /* Long file name */
    {
        /* Convert directory entry long file name to character long file name. */
        pc_cre_longname((UINT8 *)old_name, linfo);
    }
    else                            /* Short file name */
    {
        /* get file directory entry */
        pfi = (FINODE *)pobj->finode;
        pc_ino2dos(&pi, pfi);
        /* Convert directory entry short file name to character short file name. */
        pc_cre_shortname((UINT8 *)old_name, pi.fname, pi.fext);
    }

    /* Mark the old file name end. */
    p = old_name;
    op_nmend = NULL;
    while (*p)
    {
        if (*p == '.')
        {
            if (*(p+1) != '.')
                op_nmend = p;
        }
        p++;
    }
    op_exend = p;

    if (!op_nmend)
        op_nmend = op_exend;


   /* Setup the new file name pointer */
    *new_name = fname;


    /* Setup the new file name */
    p = name;
    old = old_name;

    while (*p)
    {
        if (*p == '*')
        {
            /* More the new file name. */
            if (old < op_nmend)
            {
                while (old != op_nmend)
                {
                    *fname = *old++;
                    fname++;
                }
                break;
            }
        }
        else if (*p == '?')
        {
            *fname = *old;
        }
        else
        {
            *fname = *p;
        }

        fname++; old++; p++;

        /* File name end ? */
        if ( ext && (p == (ext-1)) )
            break;
    }


    /* Setup the new file extension. */
    if (ext)
    {
        /* file name .ext */
        *fname = '.'; fname++;
        p = ext;
        old = op_nmend + 1;

        /* Setup the new file extension pointer */
        *new_ext = fname;

        while (*p)
        {
            if (*p == '*')
            {
                /* More the new file extension. */
                if (old < op_exend)
                {
                    while (old != op_exend)
                    {
                        *fname = *old++;
                        fname++;
                    }
                    break;
                }
            }
            else if (*p == '?')
            {
                *fname = *old;
            }
            else
            {
                *fname = *p;
            }

            fname++; old++; p++;
        }
    }
    *fname = '\0';

    return(YES);
}


/************************************************************************
* FUNCTION                                                              
*                                                                       
*       pc_next_fparse                                                  
*                                                                       
* DESCRIPTION                                                           
*                                                                       
*       Next upperbar file name.                                        
*       Create a filename~XXX.                                          
*                                                                       
* AUTHOR                                                                
*                                                                       
*       Kyoichiro Toda
*                                                                       
* INPUTS                                                                
*                                                                       
*       filename                            Upperbar file name.         
*                                                                       
* OUTPUTS                                                               
*                                                                       
*       YES    Success compleate.                                       
*       NO     Can't create new filename.                               
*                                                                       
*************************************************************************/
INT pc_next_fparse(UINT8 *filename)
{
UINT8       *pfr;
UINT8       *pupbar;
UINT8       *pnamend;
UINT32      tailno = 0L;
UINT32      temp;
UINT8       nm;
INT16       n = 0;
INT16       i;


    /* Defaults */
    pfr = filename;
    pnamend = pupbar = 0;

    /* Mark the upperbar opinter and filenumber opinter. */
    while (*pfr)
    {
        /* SPR245 7-20-01 this was the original code
        if ( (*(pfr+1) == '\0') || (*(pfr+1) == ' ') )
            pnamend = pfr; *****/

		if( pnamend == 0 ) /* SPR245 7-21-01 new code */
		{

            if ( (*(pfr+1) == '\0') || (*(pfr+1) == ' ') )
                pnamend = pfr;
		} /* End SPR245 new code */

        if (*pfr == '~')
            pupbar = pfr;

        pfr++;
        /* File name end ? */
        if (*pfr == '.')
            break;
    }

    /* Not use the filename upperbar and filenumber. */
    if ( (!pnamend) || (!pupbar) )
        return(NO);

    /* Take a filename number(~XXX) */
    pfr = pnamend;
    temp = 1L;
    while (pfr != pupbar)
    {
        tailno += (*pfr - '0') * temp;
        temp *= 10L;
        pfr--;
    }
    /* Next a filename number. */
    tailno +=1;

    /* How many single figures */
    temp = tailno;
    while (temp)
    {
        temp /= 10L;
        n++;
    }

    /* Set the upperbar mark. */
    if ((pnamend-n) > filename)
        *(pnamend-n) = '~';
    else
        return(NO);

    /* Set the next number. */
    temp = 1L;
    for (i = 0; i < n; i++)
    {
        nm = (UINT8) (((tailno%(temp*10))/temp) + '0');
        temp *= 10L;

        if (filename < (pnamend-i))
            *(pnamend-i) = nm;
        else
            return(NO);
    }

    return(YES);
}


/************************************************************************
* FUNCTION                                                              
*                                                                       
*       pc_fileparse                                                    
*                                                                       
* DESCRIPTION                                                           
*                                                                       
*       Copy the short file name and the short file extension to the    
*       buffer of an output from the start pointer of the file name and 
*       the extension.End each name with '\0'.  It will be              
*       unsuccessfully completed when the character that can not be used
*       in the file name is used. When the long file name uses more than
*       eight characters in the file name, uses lower case,             
*       uses ' = ' ' [ '' ] ' ' ; ' ' + ' ' , ' '  '  ' . ', or uses    
*       more than four characters in the extension, the short file name 
*       is created by using the first six characters of the long file   
*       name with an upper bar and 1following it.  The upper function   
*       that calls these function has to prepare at least nine short    
*       file name buffer and four short file name extension buffer, both